Percussive drill, hammer, or like percussive tool or machine.



A. SYKES.

PERGUSSIVE DRILL, HAMMER, 0R LIKE PERGUSSIVE TOOL 0R MACHINE.

' APPLICATION FILED JAN. 22, 1910.

1,014,979., Patented Jan. 16, 1912.

2 -SHEETS'SHEBT 1.

COLUMBIA PLANOGRAPH COq WASHINGTON, n. c.

A. SYKES.

PERGUSSIVE DRILL, HAMMER, OR LIKE PERGUSSIVE TOOL 0R MACHINE.

APPLICATION FILED JAN. 22, 1910.

1,014,979. PatentedJa11.16,1912.

2 SHBBTS-SHEIBT 2.

iii-iii Fig.5.

COLUMBIA vmmuulmvu 130., WASHING ALFRED SYKES, OF I-IUDlJERSFIELD, ENGLAND.

PERCUSSIVE DRILL, HAMMER, OR LIKE PERCUSSIVE TOOL 0R MACHINE.

Specification of Letters Patent.

Patented Jan. 16,1912.

Application filed January 22, 1910. Serial No. 539,560.

To all whom it may concern:

Be it known that I, ALFRED SYKES, a subject of King Edward VII of Great Britain, and resident of Huddersfield, in the county of York, England, have invented certain new and useful Improvements in Percussive Drills, Hammers, or Like Percussive Tools or Machines, of which the following description, in connection with the accompanying drawings, is a specification.

My invention consists in certain novel features of construction of my improvements as will be hereinafter fully described.

Referring to the drawings :Figure 1 is a plan view of a percussive drill embodying my improvements, the cover of the gear case being omitted to show the gearing more clearly; Fig. 2 is a longitudinal sectional elevation taken as on line a, b, of Fig. 1; Fig. 3 is a transverse section taken on line 0, (Z, of Fig. 1 Fig. 4 is a sectional plan view of the valve chamber; Fig. 5 is a section taken on line 6, f Fig. 1; Fig. 6 is a transverse section taken on line 9, h Fig. 5; Fig. 7 is an elevation of the screw jack, detached, for supporting the machine when at work and adjusting its height.

Referring firstly to Figs. 1 to 7 of the drawings, 1 and 2 represent two pistons adapted to work in one cylinder 3, the front or outer piston 1 being the driving piston, and the rear or inner piston 2 the drill, cutter, or hammer operating piston. Each piston may, if desired, be provided with piston rings or other devices for preventing leakage of air past same, and herein I have shown them as being so provided. The driving piston 1 has in lieu of a piston rod, a tubular extension 1 which projects outwardly beyond the cylinder 3 and works through a gland or stuffing box 4 of any approved construction and suitably supported at the front end of the cylinder. Secured to the outer end of the tubular extension 1 is a cross head 5 carrying a pin 6 on which is pivotally mounted one end of a connecting rod 7 whose opposite end is eccentrically connected to a disk or plate 7 a mounted upon a shaft 8 and adapted to be driven by worm 9 and worm wheel 10, the worm 9 receiving its motion through pinion 11 and spur wheel 12 from a motor, as 18, or like source of motion. The rotation of the disk 7 through connecting rod 7, gives a reciprocating motion to the cross head 5 and consequently to the piston 1. The cutter piston 2 has-a piston rod 2 which extends through and is adapted to slide within the driving piston 1 and its tubular extension 1 astufiing box 2 of any approved construction being provided where necessary to make a tight oint between the said piston rod and tubular eX- tension, and on the outer end of said piston rod is secured the cutter chuck 14C. The piston rod 2* is made sufliciently long to provide the necessary clearance between adjacent parts at any position of the piston. The piston rod 2 has cut in or formed thereon at its outer end 2, spiral or helical grooves or teeth which are adapted to-work through a nut 15 (see Figs. 5 and 6) provided on its circumference with a ratchet wheel 16 into the teeth of which take one, two or more pawls 16 (see Fig. 6) so that as the spirally grooved or toothed part 2 of the piston rod 2 reciprocates with the cutter piston 2, a rotary motion is imparted to same at each return or backward stroke in the manner usual in rock drills. I prefer, however, to introduce a friction clutch between the nut 15 and ratchet wheel 16 so that in the event of undue stress being put upon the cutter, the clutch will slip without doing any damage. The clutch, in this instance, comprises a series of disks 17 secured by a key or keys 17 to the ratchet wheel 16 and a series of similar disks 18 secured by a key or keys 18 to the nut 15, each disk being capable of moving laterally or longitudinally on the respective keys under pres sure exerted by a spring or springs 19, fiber washers 20 being introduced between each pair of disks to increase friction and admit of easy and cheap renewal when worn.

In a suitable position in the front portion of the cylinder 3 are a number of openings or ports 21 to admit atmospheric air to the cylinder, and at or near the rear end of the cylinder are openings or ports 22 and 28 leading to and from a valve chamber 24. The pistons 1, 2, do not work quite the length of the cylinder 3, there being a small space left between the front end of the cylinder and the face of the driving piston 1 to cushion the constantly reciprocating parts, and a space is left at the rear of the cylinder, as at 3 into which the air at the back of the piston 2 is compressed. In action, the cutter piston 2 makes a shorter stroke than the stroke of the positively reciprocated driving piston 1 by reason of the cutter or drill striking the rock, metal or other hard substance or material but, if the cutter should miss the object, the two pistons simply reciprocate together. lVhen the driving piston 1 arrives at or approaches the forward end of its stroke, it uncovers the air holes 21. through which air is admitted to the space between the pistons 1 and 2 where it is retained by the re-covering of said holes on the driving piston commencing its rearward stroke, then forming an air cushion between the two pistons by means of which the inertia and friction of the cutter piston system and cutter are overcome by the driving piston setting same into motion without shock. The two pistons thereupon complete their rearward strokes, tlfe cutter piston 2 compressing the air, which is at its rear side, in the chamber or space 3 at the back of the cylinder. hen the driving piston 1 arrives approximately at the end of its inward or return stroke, the cutter piston 2 passes beyond the port or ports 22 which is or are thus exposed to the space between the two pis ons and consequently admit of the air between the two said pistons, which has been used for cushioning purposes, passing or being forced through the said port or ports 22 past the non-return valve 25 in the valve chamber 24 (see Fig. 4-) and through the port or ports 23, to the rear end of the cylinder to maintain the pressure of air behind the cutter piston 2 against any leakage that may occur. The openings 22 are provided so that leakage of compressed air may be made good. As the air behind the piston 2 forms the whole propelling force which drives the cutter against the work, any leakage, which is unavoidable, must be promptly made good. The air is free to pass through the openings 22 at each backward stroke of the driven piston, but if the pressure of the air behind the piston is sufficient, no air actually passes through the openings 22, but escapes at the other openings as the driven piston makes its forward stroke. As the driving piston 1 now moves outward on its next forward stroke, the air in front thereof is forced out through the holes 21, removing all pressure from the front of the cutter piston 2, so that the expansion of the compressed air behind the cutter piston forces the latter forward and gives a percussive action to the cutter 14:, secured to the chuck 14, to force it into its cut, this cycle being continuously repeated as the driving piston is reciprocated by the crank and connections, the air behind the cutter piston 2 being at each return stroke thereof compressed suffi' ciently to drive out the said piston to give the percussive blow or cutting action.

It will be manifest from the foregoing I that the force at disposal for withdrawal of the cutter is enormous and this force can act equally well at any portion'of the stroke of the cutter piston, or should the cutter not enter to the full depth on any portion of the .cut by reason of its cutter meeting some obstruction and being held stationary, it will make no difference to the working of the machine as the driving mechanism will continue to reciprocate the parts without doing any damage.

The machine for mining purposes is constructed in two general forms, a large one for slower speeds and heavy cuts, and a smaller one for high speeds and light cuts. The electric or other equivalent motor 13 in the former case would generally form a part of the machine and the whole of the machine and motor be swung on a bracket 28 and column 29 provided with a screw jack 30. In the slower speed machine (Figs. 1 and 2), the rear portion of the cylinder is extended to form a gear box 32 to support the worm and worm wheel, with necessary ball or other thrust collars, the motor 13 attached to the gear case driving the worm either direct or through toothed gearing as shown, the speed being reduced by the worm gearing to a suitable extent for driving the machine or tool, or any other suitable system of gearing may be employed in place of worm and worm Wheel. The gear box 32 is preferably formed to allow of the machine being supported to work upon a slide 35 of suflicient length to permit of the said machine being fed into and out of its out by means of a feed screw 36 and nut 37, the said slide being plain or provided with ball or roller bearings, as shown in Fig. 3, and the feed nut so attached to the machine that the motion is conveyed to the latter through the medium of one or more springs 38. Considerable forces are required to accelerate and retard the pistons and parts, and, unless some provision is made,-the reaction on the machine would produce severe stresses on the supporting jack 30 and appliances, and to avoid this I allow these re-actions to move the mass of the machine and its attached motor to and fro upon the slide 35, these masses having the same periodicity as the driving crank. In addition to. transmitting movement to the machine, one of the springs 38 exerts a force constantly acting in such a manner as to keep the machine toward its out as the mean reaction on the machine in the forward direction is less than in the backward direction owing to the stoppage of the cutter piston and cutter on striking the rock or other object. In one piece with the slide 35, at, say, its middle, is a spindle 39 which passes through the boss 28 of the supporting bracket 28 and carries a worm wheel 4:0 which by means of a worm (not shown) journaled in bearings 28 in said bracket, allows of the machine being swung in a vertical direction. The bracket 28 itself is adapted to be rotated by means of a worm and worm wheel 41 around the pillar or column 29 which is fastened between the floor and roof by means of the jack screw 30. A thread is formed or cut on the outside of the column 29 and also a key is out nearly the full length of the said column. A feather in the worm wheel 41 works into the key way in the column 29 so that by rotating the threaded nut 29 the worm wheel supporting bracket, and machine, are raised or lowered, but the worm wheel 41 can not. rotate independently on the column. When the machine has finished a cut, it is raised on the column to admit of a tram being placed underneath on to which it is then lowered for removal to a fresh position.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is 1. In a percussive tool, the combination, with a cylinder having a stuffing-box at one end, of a front piston slidable in the said cylinder and provided with a tubular piston-rod also having a stufling-box, driving mechanism connected to the end of the tubular piston-rod which projectsfrom the said cylinder and its stuifing-box, said driving mechanism being adapted to reciprocate the said piston positively, and a rear piston slidable in the said cylinder and arranged wholly to the rear of the front piston and having a piston-rod which is slidable in the stufiing-box of the tubular piston-rod and which is adapted to actuate the tool or bit.

2. In a percussive tool, the combination, with a cylinder having a stufling-box at one end, of a front piston slidable in the said cylinder and provided with a tubular piston-rod also having a stuffing-box, driving mechanism connected to the end of the tubular piston-rod which projects from the said cylinder and its stuffing-box, said driving mechanism being adapted to reciprocate the said piston positively, and a rear piston slidable in the said cylinder and arranged wholly to the rear of the front piston and having a piston-rod which is slidable in the stufiing-box of the tubular piston-rod and which is adapted to actuate the tool or bit, said cylinder being also provided with a port in its side wall which is uncovered by the rear edge of the front piston at the end of its forward stroke to admit pressure fluid to the annular space between the front and rear pistons.

3. In a percussive tool, the combination, with a cylinder having a stuffing-box at one end, of a front piston slidable in the said cylinder and provided with a tubular piston-rod also having a stuffing-box, driving mechanism connected tothe end of the tubular piston-rod which projects from the said cylinder and its stufling-box, said driving mechanism being adapted to reciprocate the said piston positively, and a rear piston slidable in the said cylinder and arranged wholly to the rear of the front piston and having a piston-rod which is slidable in the stuffing-box of the tubular piston-rod and which is adapted to actuate the tool or bit, said cylinder being also provided at its rear end portion with a longitudinal passage having ports at its ends which' communicate respectively with the space between the two pistons and with the space behind the rear piston, and a non-return valve arranged in the said passage and permitting compressed air to flow through the said passage into the space behind the rear piston to compensate for leakage.

In testimony whereof I affix my signature in the presence of two witnesses.

ALFRED SYKES. Witnesses:

THOMAS H. BARRON, ELSIE M. GLEDHILL.

Copies of this patent ma}; be obtained for five cents each, by addressing the Commissioner of Patents,

. Washington, D. 0. 

